Immunostaining of human and mouse lesions with markers expressed in basal subtype lesions (Krt14 and Krt6a) revealed robust expression in the BBN-treated controls and human basal tumor, whereas there was little if any expression in lesions from mouse K5VP16;Pparg mutants or luminal lesions from human patients (Fig. 3i, m, q, u). Here, PPARG is linked to neoplasm.